William Charles "Bill" Ayers (born December 26, 1944) is an American elementary education theorist and a leader in the counterculture movement who opposed US involvement in the Vietnam War. He is known for his 1960s radical activism and his current work in education reform, curriculum and instruction. In 1969, he co-founded the Weather Underground, a self-described communist revolutionary group with the intent to overthrow imperialism, that conducted a campaign of bombing public buildings (including police stations, the US Capitol Building, and the Pentagon) during the 1960s and 1970s in response to US involvement in the Vietnam War.